Stateflow Chart Considerations

hisf_0064: Shift operations for Stateflow data to improve code compliance

ID: Title	hisf_0064: Shift operations for Stateflow® data to improve code compliance
Description	To improve code compliance of the generated code with Stateflow bit-shifting operations, do not perform:
	A	Right-shift operations greater than the bit-width of the input type, or by a negative value.
	B	Left-shift operations greater than the bit-width of the output type, or by a negative value.
Note	If you follow this and other modeling guidelines, you increase the likelihood of generating code that complies with the coding standards.
Rationale	To avoid shift operations in the generated code that might be a coding standard violation.
Model Advisor Checks	Check usage of shift operations for Stateflow data (Simulink Check)
References	DO-331 Section MB.6.3.1.b 'High-level requirements are accurate and consistent' DO-331 Section MB.6.3.2.b 'Low-level requirements are accurate and consistent' IEC 61508–3, Table A.3 (2) Strongly typed programming language IEC 61508–3, Table A.4 (3) Defensive programming IEC 62304, 5.5.3 - Software Unit acceptance criteria ISO 26262-6, Table 1 (1b) Use of language subsets ISO 26262-6, Table 1 (1c) Enforcement of strong typing ISO 26262-6, Table 1 (1d) Use of defensive implementation techniques EN 50128, Table A.4 (8) Strongly Typed Programming Language EN 50128, Table A.3 (1) Defensive Programming MISRA C:2012, Rule 10.1
Prerequisites	hisl_0060: Configuration parameters that improve MISRA C:2012 compliance
Last Changed	R2021a
Examples	Incorrect Correct Perform shift operations within the defined range of input and output signals. Correct When shift operations are more than the width of input signals, perform the explicit conversion. Since the output can hold the final value, the conversion prevents the output from being written as 0 during code generation.

hisf_0065: Type cast operations in Stateflow to improve code compliance

ID: Title	hisf_0065: Type cast operations in Stateflow to improve code compliance
Description	In Stateflow charts that use the C action language, use the := notation to protect against Stateflow casting integer and fixed-point calculations to wider data types than the input data types.
Note	If you follow this and other modeling guidelines, you increase the likelihood of generating code that complies with the coding standards.
Rationale	To avoid implicit casts in the generated code that might violate coding standards.
Model Advisor Checks	Check assignment operations in Stateflow Charts (Simulink Check)
References	DO-331 Section MB.6.3.2.b 'Low-level requirements are accurate and consistent' IEC 61508–3, Table A.3 (2) Strongly typed programming language IEC 61508–3, Table A.4 (3) Defensive programming IEC 62304, 5.5.3 - Software Unit acceptance criteria ISO 26262-6, Table 1 (1b) Use of language subsets ISO 26262-6, Table 1 (1c) Enforcement of strong typing ISO 26262-6, Table 1 (1d) Use of defensive implementation techniques EN 50128, Table A.4 (8) Strongly Typed Programming Language EN 50128, Table A.3 (1) Defensive Programming MISRA C:2012, Rule 10.1 MISRA C:2012, Rule 12.2
Prerequisites	hisl_0060: Configuration parameters that improve MISRA C:2012 compliance
Last Changed	R2021a

hisf_0211: Protect against use of unary operators in Stateflow Charts to improve code compliance

ID: Title	hisf_0211: Protect against use of unary operators in Stateflow Charts to improve code compliance
Description	To improve code compliance of the generated code:
	A	Do not use unary minus operators on unsigned data types.
Note	The MATLAB® and C action languages do not restrict the use of unary minus operators on unsigned expressions.
Rationale	Improve code compliance of the generated code.
Model Advisor Checks	Check Stateflow charts for unary operators (Simulink Check)
References	DO-331 Section MB.6.3.1.b 'High-level requirements are accurate and consistent' DO-331 Section MB.6.3.2.b 'Low-level requirements are accurate and consistent' IEC 61508–3, Table A.3 (2) Strongly typed programming language IEC 61508–3, Table A.4 (3) Defensive programming IEC 62304, 5.5.3 - Software Unit acceptance criteria ISO 26262-6, Table 1 (1b) Use of language subsets ISO 26262-6, Table 1 (1c) Enforcement of strong typing ISO 26262-6, Table 1 (1d) Use of defensive implementation techniques EN 50128, Table A.4 (8) Strongly Typed Programming Language EN 50128, Table A.3 (1) Defensive Programming MISRA C:2012, Rule 10.1
Last Changed	R2017b